Many kinds of measurements may not be satisfactorily performed with discrete galvanomagnetic sensors comprising a single, or even dual sensing elements. In general, the accuracy of a measurement can be greatly improved by the use of sensor arrays. Furthermore, a sensor array is conducive to a fault tolerant and/or a fail-soft sensing system. Although optical sensor arrays are well known and readily available, generally, they are not suitable for automotive or other industrial applications exposed to a dirty environment.
As disclosed in U.S. Pat. No. 6,201,466, titled, “Magnetoresistor Array”, commonly assigned to the same assignee of the present invention, the inventor of the present invention has demonstrated a state-of-the-art magnetoresistor array that provides superior resolution and improved sensing capability. The foregoing patent innovatively addresses integrated-circuit topologies that have enabled the integration in a single die of a magnetoresistor array.
A user-programmable microprocessor or digital signal processor (DSP) would be desirable to process the data from the sensor array so that any unique processing needs may be appropriately addressed, without having to undergo any expensive and time-consuming redesign and/or retesting of the sensor array. For example, this DSP may be configured with appropriate algorithms for specific sensing tasks. The sensor manufacturer could include a family of some standard algorithms in the DSP. However, it is envisioned that end users could also develop and employ their own customized algorithms, which would allow them to create a uniquely configured sensor array using essentially the same sensor array hardware purveyed by the sensor array manufacturer.
Accordingly, for certain applications, it may be desirable to offer a single chip solution that embeds both the sensor array and the DSP. For these applications there is a need of providing a compact and relatively inexpensive array of galvanomagnetic sensors and processor integrated on a single semiconductor die. For other applications, where a DSP may be externally available to the end user, it would be particularly desirable to provide data interface techniques that would allow reducing the number of interface pins of the chip. It would be further desirable to provide data interface techniques that would allow the user to implement reliable and accurate data transfer between the sensor array and any external DSP. It would be further desirable to provide signal conversion techniques appropriately matched to the specific dynamic range provided by the sensor array.